<!DOCTYPE html>
<meta charset="utf-8">
<title>ok</title>
<script>
function try_fetch(url) {
  return fetch(url).then(
    response => {
      return "ok";
    },
    err => {
      return err.name;
    }
  );
}
function try_fetch_status(url) {
  return fetch(url).then(
    response => {
      return response.status;
    },
    err => {
      return err.name;
    }
  );
}
</script>
